1. Field of the Invention
Embodiments of the invention relate to handheld projectors. More particularly, embodiments provide a device-mounted camera and a hybrid visible/infrared light projector configured to track multiple independent projected images in relation to one another.
2. Description of the Related Art
Over the last decade, image projection systems have been developed that are small enough to fit comfortably within a person's hand. Such devices (sometimes referred to as pocket projectors or mobile projectors or pico projectors) provide a handheld device that can project images onto any nearby viewing surface.
Additionally, a handheld projector can be connected to (or integrated with) other portable devices such as mobile phones, personal digital assistants, and digital cameras. Handheld devices such as these provide sophisticated computing platforms, complete with large display areas, touch sensitive surfaces and cameras, among other components. Further, the computing power of these devices has steadily increased; allowing sophisticated computing applications to be executed from the palm of one's hand. For example, handheld devices now frequently include computing hardware capable of rendering 3D graphics images in real time, and a variety of rendering applications are available for handheld devices. Handheld projectors can be connected to (or integrated with) these types of portable devices. When combined with (or connected to a computing system) a handheld projector can project any image generated by the handheld device onto a viewing surface.
The relatively large size of projected images allows them to be easily seen by multiple users. However, allowing two devices (and projected images) to interact with one another has typically required a controlled environment. For example, one published approach has been to attach a number of retroreflective markers to a handheld projector, which are then tracked by the motion capture system installed in the environment. Alternatively, another approach has been to instrument the environment (e.g., with markers visible to a sensor on the handheld device). Both approaches rely on the handheld projected being used within the controlled environment.